Measure Twice is a skill published by agensi that installs 12 behavioral rules into an AI agent to reduce a specific class of repeated mistakes. Each rule was derived from a real session failure rather than theoretical best practices. The rules change how an agent approaches every task it receives.
The core loop the skill enforces is: quote the user’s exact words before acting, read the current state of any file before editing it, write a single sentence describing the intended change in the form “Currently X, want Y, changing Z”, implement the change, then re-read the file to confirm the result matches what was requested. This verification step replaces the common pattern of an agent declaring a task complete without checking.
The rules specifically address the following failure modes: editing files without reading their current contents first, paraphrasing a user’s request and dropping the detail that mattered, retrying the same broken fix with only minor variation, placing changes in the wrong file or wrong scope, breaking adjacent code while fixing a targeted issue, and losing track of the original request after several exchanges.
Measure Twice is a skill with no tools and no external service connections. It carries no package version, license, or repository. It is appropriate when the primary problem is agent carelessness or loop failures in coding workflows, not when additional integrations or data access are needed.